1. Field of the Invention
The present invention relates to intravenous catheters, and particularly to an intravenous catheter insertion apparatus which prevents exposure of medical personnel to accidental needle sticks and to blood borne pathogens during the insertion of an IV catheter.
2. Description of Related Art
Intravenous (IV) therapy is a versatile technique used for the administration of fluids. It has been used for such purposes as the maintenance of fluid and electrolyte balance, the transfusion of blood, administration of nutritional supplements, chemotherapy, and the administration of drugs and medications. Fluids may be administered intravenously by injection through a hypodermic syringe, or intermittently or continuously by infusion using a needle or a plastic or silicon catheter.
Although there are many advantages to be derived from the intravenous administration of fluids, the past two decades have brought heightened awareness of the risks of propagating infectious diseases associated with the technique, particularly due to the HIV virus. One consequence of this heightened awareness has been the development of various devices to reduce the risk of spreading infectious diseases. Probably the majority of devices which have been developed are concerned with the danger of accidental puncture wounds occurring through use of the hypodermic syringe needle or to the particular needle or trocar used to introduce a continuous infusion IV catheter.
Continuous infusion IV therapy may be generally divided between peripheral IV therapy and central venous IV therapy, depending on the site of administration. Catheters used for peripheral IV therapy tend to be short, between 3/4" and 11/4" long, or occasionally 2" long for insertion into a deep vein. Catheters for central venous IV therapy tend to be much longer, and are outside the scope of the present invention.
A peripheral IV catheter is made of soft, flexible plastic or silicon, generally between 16 gauge and 24 gauge. In the conventional venipuncture the catheter is inserted into a vein in the patient's hand, foot, or the inner aspect of the arm or any vein in the body that will accept an IV catheter. When inserting a peripheral IV catheter, an IV infusion set is prepared, the IV tubing being filled with fluid and any air eliminated from the tubing, closing the fluid clamp. A tourniquet is applied proximal to the venipuncture site, and a variety of techniques are used to dilate the vein. Wearing disposable gloves, the venipuncture site is cleansed and a vein is retracted or anchored by placing a thumb over the vein about two to three inches distal to the site. A catheter with a stylet advanced through its lumen so that the pointed tip extends beyond the cannula of the catheter, or a butterfly needle, is introduced into the vein by inserting the bevel into the vein at about a 20.degree. to 30.degree. angle with the bevel facing up in order to pierce one wall of the vein. Blood return in the tubing of the butterfly needle or the flashback chamber of the over the needle catheter indicates that the vein has been entered, and the needle is lowered towards the skin and the catheter is advanced about 1/4" into the vein. The stylet is loosened and the catheter is gently advanced farther up into the vein until the hub of the catheter is against the venipuncture site. The tourniquet is loosened and the needle or stylet is removed from the catheter. The needle adaptor of the infusion tubing is secured to the hub of the catheter, and the roller clamp is opened. The flow rate may be controlled either by adjusting the roller clamp or an infusion pump, and the catheter is secured to the venipuncture site by gauze and adhesive tape.
During this process medical personnel are exposed to the possibility of an accidental needle puncture or to contamination from the back flow of the patient's blood from the venipuncture site.
Many protective devices have been developed to prevent accidental needle puncture during the insertion of the IV catheter. U.S. Pat. No. 4,444,203, issued Apr. 24, 1984 to A. Engleman, shows a combination device for inserting an IV catheter and withdrawing blood. The device includes a hub having a hypodermic needle at one end adapted for releasably holing an over the needle catheter, and a vacuum container penetrating needle covered by a resilient sleeve at the other end of the hub. A vacuum container for collecting blood slides over the vacuum needle, compressing the sleeve so the needle penetrates the sleeve. The catheter may be inserted with or without the vacuum container in place, blood samples are collected, and the entire assembly except the catheter itself are removed.
Other blood collection devices are shown in U.S. Pat. No. 4,509,534, issued Apr. 9, 1985 to M. J. Tassin, Jr. and U.S. Pat. No. 4,819,659, issued Apr. 11, 1989 to D. L. Sitar. The Tassin device describes a device for collecting blood which taps into an IV catheter system through an entry means, but does not describe a catheter insertion system or apparatus. The Sitar patent describes a blood withdrawing device with a needle guard to prevent accidental puncture wounds, including a guard which slides forward to cover the needle, locking on a lock which is molded onto the shaft of the needle to lock the guard in position.
Needle shields or sheathes have been developed which are slidable, e.g., U.S. Pat. No. 5, 011,475, issued Apr. 30, 1991 to Richard A. Olson (sheath slidable in slots defined in barrel of syringe); pivotal, e.g., U.S. Pat. No. 5,603,699, issued Feb. 18, 1997 to Jerry P. Shine (shield pivotally attached at base of syringe and pivotally operated by lever connected to gear mechanism); and frangible, e.g., U.S. Pat. No. 5,344,404, issued Sep. 6, 1994 to Carl L. Benson (shield in different segments secured by frangible means such as plastic shrink wrap). Some of the shields and sheathes are open over the tip of the needle, such as U.S. Pat. No. 5,267,972, issued Dec. 7, 1993 to Wayne W. Anderson (sheath spring biased to normally enclose needle, retracts around barrel of syringe when pressed against patient' skin), while others lock over and enclose the tip of the needle after use, such as U.S. Pat. No. 5,366,447, issued Nov. 22, 1994 to Carol A. Gurley (sleeve sliding over barrel of hypodermic syringe, the sleeve having a seal at the end to seal the sleeve over the needle when fully extended) and U.S. Pat. No. 5,685, 860, issued Nov. 11, 1997 to Chang, et al. (needle with a cap attached by a sleeve to the needle hub, capping needle tip after the needle is removed from the catheter hub).
International Patent No. WO 92/04063, published Mar. 19, 1992, shows a protective assembly for use with a syringe or a Y-tube. The device includes a hollow body connecting to a syringe by a Luer Lok connector at one end and to a needle at the other end, the exterior of the hollow body having ratchet teeth, and a protective sleeve slidable over the hollow body, the interior of the protective sleeve having a pawl which engages the ratchet teeth to prevent retrograde movement of the protective sleeve once the protective sleeve has been covered by the sleeve.
The present invention is an intravenous catheter insertion apparatus which includes a catheter integral with an a pre-slit injection site, a blunt cannula adapted for penetrating the pre-slit injection site, and a needle tube having a needle of sufficient length to pass through the blunt cannula, injection site and catheter, leaving the tip end of the needle projecting through the end of the catheter. After the catheter has been inserted into the venipuncture site, the needle tube and blunt cannula may be removed, the septum on the injection site preventing blood from spilling or spurting out of the catheter, thereby preventing the spread of blood borne pathogens.
International Patent No. WO 90/12606, published Nov. 1, 1990, shows a pre-slit injection site used in combination with a blunt cannula (FIGS. 5A and 5B), the injection site used in combination with a catheter (FIGS. 2A and 2B), the injection site and blunt cannula used in combination with a syringe (FIG. 4A), and the injection site and blunt cannula used in combination with IV tubing. However, the patent does not disclose an injection site integral with a catheter. Further, the patent does not describe the use of the combination to perform a venipuncture. The syringe is only described in combination with the blunt cannula for use in injecting fluids, and is shown in use with the blunt cannula without a needle.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.